Telesurgical systems are well-known and commonly used to robotically manipulate objects such as tools in remote or other environments where it is advantageous for a human not to do so in person. One example of such a system is the minimally invasive robotic surgery system described in commonly owned U.S. Pat. No. 6,699,177 entitled “Method and Apparatus for Performing Minimally Invasive Surgical Procedures,” which is incorporated to the extent consistent herein by this reference.
To manipulate the remote object, a human operator or user of the telesurgical system manipulates or otherwise commands a locally provided master manipulator. Such commands to the master manipulator are then translated as appropriate, and sent to a remotely deployed slave manipulator. The slave manipulator then manipulates the object according to the user's commands.
In order to enhance the user's ability to “feel” the effects of his or her control inputs, force reflection is commonly included in telesurgical systems by having the remote slave manipulator feed back force or other motion relative signals to the master manipulator so that the user feels as if he or she is manipulating the controlled object directly by hand.
One problem with such force reflection telesurgical systems, however, is that a large feedback gain and/or signal filtering may cause the closed-loop control system between the master and slave manipulators to go unstable. Without such gain and/or filtering, however, the user may not properly feel objectionable force levels being applied by the manipulated object against obstructions in its path. In a minimally invasive surgical application such insensitivity to tool forces can result in the surgical tool exerting excessive forces so as to, for example, injure the patient or otherwise affect the safety or comfort of the patient in some manner.